Keyboard for calculating machine



Aprifi 1, 1958 A. J. MALAVAZOS KEYBOARD FOR CALCULATING MACHINE 3 Sheets-Sheet 1 Filed July 12, 1954 April 1, 1958 A. J. MALAVAZOS KEYBOARD FOR CALCULATING MACHINE 3 Sheets-Sheet 2 Filed July 12, 1954 April 1, 1958 A. J. MALAVAZOS KEYBOARD FOR CALCULATING MACHINE :5 Sheets-Shegt 3 Filed July 12, 1954 Patented Apr. 1, 1958 Arthur J. Malavazos, Oakland, Calif., ass

inc, a corporation of Calif Application July 12, 1954-, Serial No. 442,870

Claims. (Cl. 235ll45) This invention relates to calculating machine keyboards and more particularly to the combination of a full keyboard having ordinally arranged rows of digit keys with the keys in each row numbered from O to 9, and guide bars for guiding the lower ends of the keys.

It is among the objects of the invention to provide an improved calculating machine keyboard having a rigid frame of simple construction in which the key stems are slidably supported for substantially Vertical movement and guide means positioned below the keyboard and accurately guiding the bottom ends of the key stems so that large tolerances are permitted in the lit between the key stems and the frame and wear of the key stems and frame has no tendency to render the action of the keyboard inaccurate; Which provides a construction in which thc keyboard unit is automatically centered when assembled in the machine so that no adjustment of the keyboard relative to the remainder of the machine is required to compensate for any misalignment of the keyboard or associated machine parts or for any departure within the range of practical tolerance of the keyboard or machine parts from their theoretical shape and dimensions; which permits the selection bar actuating pins on the key stems to freely follow the paths of movement determined by the guide means and rigidly connects these pins through the corresponding selection bars with the associated selection gears so that the selection gears will be accurately positioned relative to the corresponding actuating gears or drums for the particular digits selected and will be firmly held against aberrant movements which tend to reduce the proper meshing of the selection gears with the actuator gears or drums; which has means for releasably latching depressed keys in depressed position and for releasably locking the latching means to hold the keys in either raised or depressed condition to retain a selected value in the keyboard; which has means for releasing all keys from the locking means at the end of a calculating operation; which can be used with various models of calculating machines having full keyboards; and which is simple and economical to manufacture, durable in use, and accurate in operation.

Other objects and advantages will become apparent from a consideration of the following description and the appended claims in conjunction with the accompanying drawings wherein:

Fig. 1 is a longitudinal cross-sectional view through a keyboard illustrative of the invention;

Fig. 2 is a fragmentary perspective view of the keyboard; and

Fig. 3 is a cross-sectional view in the same plane as, or one parallel to, the plane of the section of Fig. 1.

While the keyboard may be used in various types of calculating machines using a full keyboard, in the form illustrated and herein disclosed, it is particularly adapted for use in the calculating machines manufactured by the Friden Calculating Machine Company of San Leandro, California, as exemplified in the Friden Patents No.

i 2,229,889, of January 28, 1941, and No. 2,294,083, of August 25, 1942.

With continued reference to the drawings, the keyboard has a frame, generally indicated at 10, and digit keys, as generally indicated at 11, slidably mounted in the frame for substantially vertical movement.

in the conventional keyboard construction as now used in calculating machines, such as the Friden calculating machine mentioned above, the keyboard frame comprises a plurality of tubular frame members of rectangular cross-sectional shape, disposed in side-by-side relationship and held together by sets of tie rods extending transversely therethrough. Conventionally, there are as many sets of tie rods as there are digit keys in an ordinal key row, each set including an upper and a lower tie rod disposed in spaced-apart and parallel relationship to each other. Each key stem is provided with a longitudinally extending slot through which the tie rods of the corresponding set of tie rods extend and each tubular frame member is provided in its upper and its lower side with elongated key stem receiving apertures or slots so arranged that each aperture in the lower side registers with an aperture in the upper side.

This is an expensive and complicated construction, and one in which it is difficult to hold the manufacturing tolerances required for the fit of the key stems in the frame slots and of the tie rods in the key stern slots, required for this type of keyboard construction. Further, this type of construction provides a frame structure having the interior of the frame so obstructed that it is not practicably possible to place control devices or other mechanisms within the frame.

Also, with this type of keyboard there is no flexibility ofthe positioning of the key stems relative to the keyboard frame. The keyboard assembly therefore has to be manually adjusted relative to the selection bars and keyboard supporting portion of the machine frame to compensate for any variations of the keyboard and actuator supporting structure from ideal conditions and provide the best condition of meshing of the selection and actuator gears that can be obtained under the circumstances.

in the improved keyboard assembly of the present invention, the frame comprises a flat upper plate 12 and a flat bottom plate 13 held in spaced-apart and parallel reiationship to each other by spacing fasteners 14 located at selected positions over the area of the plates, and spacing tabs 15 extending between the plates one at each front corner of the frame. The plates 12 and 13 are of somewhat elongated, rectangular shape and are provided with apertures arranged in ordinal rows extending longitudinally of the plates. The apertures are elongated in the direction of the length of the corresponding rows and each aperture in the upper plate 22 is in registry with a corresponding aperture in the lower plate 13.

Each key ill comprises a flat stem it; extending slidably through mutually registering apertures in the upper and lower frame plates 12 and 13, with the major crosssectional dimension of the stems extending longitudinally of the rows in which the keys are disposed. Each stem carries on its upper end, above the upper plate l2, a key head, or top, 2d and carries near its lower end, below the lower plate 13, a perpendicularly projecting pin 21. A compression spring 22 surrounds each key stem between the upper surface of the top plate 12 and the lower end of the corresponding head 20 and resiliently urges the key upwardly to a position at which the corresponding pin 2f engages the bottom surface of the lower plate 13. Preferably, the bottom surface of the lower plate is provided with pads of resiliently elastic material, such as rubber or cork, so that no noise will be produced when the keys are stopped in their upward movement by engagement of the pins with the bottom of the plate 13.

Each key stem 18 is provided in its rear edge and between the plates 12 and 13 with a notch 24 of rectangular shape. The width of the lower end portion of each key stem is reduced by recessing the lower portion of the rear edge of the stem, the reduced lower end portion being joined to the remainder of the rear edge of the key below the corresponding notch 24 by an upwardly and rearwardly inclined shoulder 25. A plurality of latch bars 26 are disposed in parallel arrangement on the upper surface of the lower frame plate 13 and extend longitudinally of the frame plate, there being one latch bar for each ordinal row of digit keys. Each latch bar is provided with a series of slots 28 spaced apart longitudinally of the bar and elongated in the direction of the length of the bar. Each of the key stems 13 extends through the appropriate slot 28 in the corresponding latch bar 26. Near their forward ends, the latch bars extend through corresponding apertures 29 in an upwardly offset, transversely extending flange portion 34 of the bottom plate. At their rear ends these bars extend through corresponding apertures 31 in an upwardly directed fiange 32 extending along the rear edge of the plate 13.

A flat partition member 34 extends perpendicularly between the upper and lower frame plates 12 and 13 intermediate the length of these plates and transversely thereof. This partition member carries on its rear side a flat spring member 35, the lower portion of which is notched to provide separate spring fingers 36, each of which is engaged at its lower end in an aperture in the corresponding latch bar 26. The spring fingers resiliently urge the latch bars forwardly to a predetermined home position in which the rear ends of the apertures in the latch bars are substantially in engagement with the recessed lower end portions of the rear edges of the key stems 18.

With this arrangement, when a key is depressed, the corresponding latch bar 26 is first moved rearwardly by the key stem shoulder 25 against the force of the associated spring finger 36 to permit the portion of the key stern between the shoulder 25 and the notch 24 to pass through the corresponding aperture in the latch bar. When the notch 24 comes into registry with the aperture or slot in the latch bar, the spring finger 36 forces the latch bar forwardly to engage the portion thereof at the rear end of the key stem receiving slot in the notch 24- to hold the key in latched-down position. The portion of the rear edge of each key stem between the upper corner of the shoulder and the bottom corner of the corresponding notch 24 is inclined upwardly and slightly forwardly so that, if a key in a particular row has already been depressed, depression of another key in the same row will move the associated latch bar 26 rearwardly distance sufiicient to release the previously depressed key before the key being depressed reaches its fully depressed position. Also, the latch bars 26 are provided at their forward ends with downwardly directed abutment formations 38 which are engaged in a Well-known manner, by a keyboard clearing bail rocked either manually, or automatically by operation of the calculating machine, to release all of the depressed keys of the keyboard at the will of the operator or at the end of a calculating operation.

Each latch bar 26 is provided intermediate its length with an upwardly projecting stop pin 4-9, these pins being arranged substantially in a straight line transversely of the keyboard frame when the latch bars are all in their home position. A bail 41, associated with the pins, has a transverse portion, or bar, 42 extending transversely of the frame between the frame plates 12 and 13. The bail is mounted on legs, as indicated at 43, extending rearwardly one from each end of the bar 42, the legs being rigidly mounted on a rock shaft 44 which also extends transversely of the frame between the frame plates 12 and 13. The bail cross-member 42 is positioned just rearwardly of the stop pins 40 on the latch bars 26 and has two operative positions in one of which, as illustrated in Fig. 1, its rearwardly curved lower edge 45 is above the pins 40 so that the latch bars 26 are free to move rearwardly so that the keys of the keyboard can be freely depressed and raised, and in the other of which the lower edge portion of the bar 42 is disposed against the rear sides of the pins 4t) so that the latch bars are releasably locked in position to hold depressed keys down and undepressed keys up to thereby retain a selected value in the keyboard. The shaft 44 is rocked to move the bail crossbar 42 between its two positions by suitable linkage means which may be of a form already known to the art, or by any suitable arrangement devised in connection with a calculating machine to which the keyboard is applied.

The keyboard, as illustrated in Fig. l, is particularly arranged for use in a calculating machine having square root extracting mechanism, such as the machine disclosed in patents of February 28, 1956, Nos. 2,736,493 and 2,73 6,494, issued to Grant C. Ellerbeck for Square Root Calculating Machine or application Serial No. 419,402, filed March 29, 1954, by Grant C. Ellerbeck, for Squaring Mechanism, and assigned to the assignee of this application.

In this arrangement, instead of the usual 0 keys disposed one at the front end of each row of digit keys, the 0 keys are replaced by decimal keys 48 disposed one at the front end of each space between two adjacent rows of digit keys. Each of the decimal keys has a fiat stem 49 slidable through aligned apertures in the upper and lower frame plates 12 and 13. Each key stem 49 is provided with a forwardly directed shoulder bearing on the upper edge of the cross-member 50 of a bail 51 having legs, as indicated at 52, extending rearwardly one from each end of the cross-member 5i and mounted at their rear ends on a rock shaft 53. The rock shaft 53 extends transversely of the keyboard frame between the plates 12 and 13 and is rotatably mounted at its ends in frame supported brackets, one of which is indicated at 54. Some of the key stems 49 have rearwardly directed shoulders which bear on the top edge of a cross-member 55 of a bail 56 having legs 57 extending rearwardly one from each end of the cross-member 55 and also mounted at their rear ends on the rock shaft 53.

Selection bars, as indicated at 59 and 69, are mounted for longitudinal movement thereof below the rows of keys ill, there being two selection bars disposed in parallel relationship below each row of keys with one selection bar 59 disposed at the left-hand side and the other selection bar 60 disposed at the right-hand side of the lower end portions of the key stems 18 of the corresponding row of keys. Each selection bar is mounted near its forward end on the upper end of a pivoted link 61 and near its rear end on the upper end of a pivoted link 62, in a manner well known to the art, for free longitudinal movement of the bars. The front ends of the bars are guided in apertures provided in a frame member 63 which extends transversely of the machine below the front portion of the keyboard frame 10. The bars 5% and 69 are provided in their upper edges with notches having rearwardly and downwardly inclined rear cam edges which are engaged by the pins 21 carried by the corresponding key stems to impart forward movements to the selection bars when the keys are depressed, the inclination of the cam edges being ing row of keys, these pins extending to the right from the corresponding key stems. The two selection bars 59 and 6t) normally condition the selection gears of a Thomas type actuating mechanism, such as that used in the well-known Friden calculating machine.

in such an actuating mechanism, a plurality of actuator shafts 38 are disposed in spaced-apart and parallel relationship with their center lines in a plane substantially parallel to the plane of the longitudinal center lines of the selection bars 59 and tit). Each actuator shaft is journalled at its front end on the transverse frame plate 72 and at its rear end in a transverse frame plate 82 disposed rearwardly of, and substantially parallel to, the plate 72.

A plurality of square shafts 83 are disposed above and parallel to the actuator shafts 8t) and are journalled 1n the transverse frame plates 72 and 82. In the well-known Friden calculator there are twice as many square shafts as actuator'shafts, disposed one at each side of each actuator shaft. in this machine, each actuator shaft carries two stepped drums, or gears, 85, one for each of the adjacent square shafts. Each drum 85 is divided longitudinally into two parts and each square shaft carries two selection gears 86 and 37, slidably mounted thereon for cooperation, one with each part of the corresponding actuator drum 85.

The left-hand selection bar 59 of the corresponding order has a rearward extension terminally connected by a yoke with the forwardly disposed selection gear 86 so that, when the bar 59 is longitudinally moved by depression of selected 1 to 5 keys of the corresponding key row, the gear 56 will be moved along the square shaft 83 and positioned to mesh with the appropriate sector of the corresponding portion of the actuator drum 85. The right-hand selection bar so has a rearward extension terminally connected by a yoke 89 with the rearwardly disposed selection gear 87 of the same order and is effective to properly position selection gear 5'7 along the corresponding portion of actuator drum 555 in response to the depression of a selected 6 to 9 key of the same order.

The actuator shafts are driven from a common drive shaft through bevel gear connections 91 and the square shafts 83 are drivingly connected to the associated register by means well known to the art.

Flat guide plates as of elongated, rectangular shape are disposed one between each two adjacent pair of selection bars 59 and to. Each of these guide plates has a straight upper edge-disposed immediately below, and substantially parallel to, the bottom surface of the lower keyboard frame plate 13. Each guide plate is supported at its front end in the fixed, transverse frame member 63 and is rigidly supported at its rear end in the fixed, transversely extending frame member 72 which provides a common support for the rear ends of the guide plates and the front ends of the actuator shafts.

Each of the frame members as and 72 is provided in its upper edge with spaced-apart notches receiving the front and rear end portions of the guide plates 68 to rigidly hold the guide plates in parallel planes perpendicular to the plane of the top edges of the frame members. Each guide plate is provided near its front end with an abutment shoulder as hearing against the rearward side of transverse frame member 63, and near its rearward end with notch 71 receiving the upper portion of transverse 1 member 72. These connections between the guide plates and the supporting frame members rigidly hold the guide plates against longitudinal movement, and the frame member 72 holds the guide plates 63 and actuator shafts against relative longitudinal movement.

Each guide plate is also provided with a series of notches 73, respectively disposed in alignment with the selection bar actuating pins of a key row. Each of the notches '73 is rectangular in shape having a length at least as great as the maximum movement of the pins 21 away from, and toward the bottom surface of, the plate 13 and having a width substantially the same as the diameter of the pins, there being only sufficient clearance between the pins and the sides of the notches 73 to permit free vertical movements of the corresponding keys. The corners of each plate '68 at the upper end of each of the notches '73 therein are beveled, substantially at a 45 degree angle, as indicated at '74, to guide the pins 21 into the corresponding notches when the keyboard assembly is being installed in a machine. Because of the loose fit of the key stems in the keyboard frame apertures, the pins will move easily into the corresponding guide plate notches and the keyboard as sembly will fit into place without adjustment of its position with the pins 21 in the corresponding notches '73.

The pins directed to the left from the lower ends of the l to 5 keys of a key row will be received in the notches of the guide plate as disposed at the left-hand side of the corresponding pair of selection bars 59 and us, while the pins projecting to the right from the 6 to 9 keys of the same row are somewhat elongated and will be received near their outer ends in the corresponding notches of the guide plate 6-3 disposed at the right-hand side of the corresponding pair of selection bars. There is thus only one guide plate for cash key row plus one extra guide plate, so that there is a guide plate at the outer side of the first row of keys and at the outer side of the last row of keys.

With this arrangement, it is not necessary to maintain close tolerances on the apertures in the keyboard frame plates 12 and through which the key stems extend, nor is it necessary to maintain accurate tolerances on the edges of the key stems. The key stems and the key stem receiving apertures in the keyboard frame plates are so formed that the keys will slide freely through the plates, the apertures in the lower plate 13 being preferably materially longer than the width of the lower portions of the key stems so that the stems have a sloppy fit in the apertures in the bottom frame plate. With an initial loose fit between the key stems and the key stem receiving apertures in the keyboard frame plates 12 and 13, it is apparent that standardized fittings between the keyboards and machine frames may be provided and the keyboard assembly can be readily dropped into place in the machine and wear at the ends of the apertures or on the edges of the key stems will not disadvantageously affect the operation of the keys or the accuracy of the movements of the selection bars by the key stem carried pins since the pins are firmly held in proper paths of travel by the notches in the guide plates ea. The guide plates take up the reaction against the pins to forward movement of the corresponding selection bars 59 and as, and the selection gears are thus accurately moved to proper positions along the corresponding square shafts and aberrant movements of the selection gears are eliminated. Also, there is no material wear on the sides of the notches '73 in the guide plates since the pins are of smooth, cylindrical shape and of a hard material and slide along the edges of the notches with a negligible amount of friction. it, however, after a long period of use, there should be any noticeable wear of the guide plates 68, it would be a simple matter to replace these guide plates in a machine with new plates, permitting continued use of the same keyboard assembly. The cost of replacing the guide plates would be negligible compared to the cost of replacing the entire keyboard or removing the machine permanently from operation, as is necessary with present keyboard constructions.

Because of the open construction of the frame of this improved keyboard and the standardized fitting between the keyboard and the machine frame, the keyboard will interchangeably fit different machines, such as eight and ten row keyboard machines, provided with various mechanisms and improvements, such as, special multiplying and dividing mechanisms, squaring and square root extracting mechanisms and interregister transfer mechanisms.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are, therefore, intended to be embraced therein.

What is claimed is:

1. In a calculating machine, a machine frame, a keyboard detachably mounted on said machine frame and comprising spaced apart and substantially parallel upper and lower frame plates apertured to receive key stems, and digit keys disposed in ordinal rows and each including a flat key stem extending slidably through said frame plates, a head on the upper end of the stem and a pin projecting perpendicularly from the stern near the lower end thereof, and selection slides mounted for longitudinal movement on said machine frame below said lower keyboard frame plate and having in their upper edges notches engaged by the corresponding stem carried pins to differentially position said slides as said keys are so actively depressed, guide plates fixedly mounted on said machine frame below said lower keyboard frame plate and extending along the lower end portions of the rows of key stems, each guide plate having therein notches which receive the corresponding pins when the keys are depressed and guide said key stems in their movements relative to said keyboard frame plates.

2. in a calculating machine, a frame, a keyboard including a frame structure fixedly mounted relative to said machine frame, keys disposed in ordinal rows and having stems extending slidably through said frame structure and pins projecting perpendicularly from end portions of said stems, and selection bars slidably mounted on said machine frame below said keyboard and extending along said key rows for engagement by said pins when said keys are selectively depressed, guide plates fixedly mounted below said keyboard and extending along said selection bars and having notches therein receiving said pins and guidin said pins in the movements of the key stems incident to depression of the corresponding keys.

3. in a calculating machine, a keyboard including frame structure and digit keys disposed in ordinal rows and each having a stem extending slidably through said frame structure, and selection slides slidably mounted below said keyboard along the key rows and engaged by said key stems for differential movement by depression of said digit keys, rigid guide means disposed below said frame structure and having openings therein receiving key stem portions when said keys are depressed and guiding said key stems in their movements incident to depression of the corresponding keys.

In a calculating machine, a keyboard including a frame structure, keys disposed in ordinally arranged rows and having stems extending slidably through said frame structure and pins projecting perpendicularly from the end portions of said stems at one side of said frame structure, and guide plates extending along said key rows below said frame structure and having straight edges adjacent and substantially parallel to said one side of said frame structure and notches therein spaced along and opening to the straight edges thereof for receiving the corresponding pins when said keys are depressed and guiding said pins in their movements incident to depression of said keys, said notches being disposed substantially perpendicularly to said one side of said frame structure and having a width not materially greater than the diameter of said pins.

5. In a calculating machine, a keyboard including a frame structure, keys disposed in ordinally arranged rows and having stems extending slidably through said frame structure and pins projecting perpendicularly from the end portions of said stems at one side of said frame structure, guide members disposed between the rows of key stems at said one side of said frame structure and having notches spaced along said key rows and extending perpendicularly from said one side of said frame for receiving and guiding the corresponding pins as the keys are depressed, said notches having a width not materially greater than the diameter of said pins and having outwardly beveled open ends adjacent said one side of said frame.

6. In a calculating machine, a machine frame, a keyboard including a frame structure, keys disposed in ordinally arranged rows and having stems extending slidably through said frame structure and pins projecting erpendicularly from the end portions of said stems at one side of said frame structure, guide members mounted in said machine frame and disposed between the rows of key stems at said one side of said frame structure and having openings therein respectively receiving said pins and guiding said pins in their movements away from and toward one side of said frame structure incident to depression and release of said keys.

7. In a calculating machine, a frame structure including a transverse frame member, a keyboard mounted on said frame structure and including a fiat keyboard frame and ordinally arranged rows of key stems extending slidably through said keyboard frame and each having at its end at one side of said keyboard frame a perpendicularly projecting pin, selection bars extending along said key rows at said one side of said keyboard frame and having cam notches in the edges thereof for engagement by said key stem carried pins to provide differential longitudinal movement of said selection bars when said keys are selectively depressed, means in said frame structure for supporting each selection bar for longitudinal movement, and guide plates extending along said selection bars at said one side of said keyboard frame and each rigidly connected at one end to said transverse machine frame member, said guide bars having notches spaced apart longitudinally thereof and individually receiving said key stem carried pins to guide said pins in their movements incident to the depression and release of the keyboard keys and rectify the differential positioning of said selection bars.

8. In a calculating machine, a machine frame, a keyboard mounted on a portion of said machine frame and comprising a flat keyboard frame provided with key stem receiving apertures and keys arranged in ordinal rows and having stems extending slidably through the keyboard frame, and guide means rigidly mounted on said machine frame below said keyboard frame and constraining the adjacent ends of said key stems to rectilinear movements as the keys are selectively depressed and released.

9. In a calculating machine having a frame, and selection mechanism mounted in said frame and including selection bars ordinally arranged in parallel relationship, a keyboard frame mounted on the machine frame, and keys having stems extending slidably through said keyboard frame and engaging said selection bars to differentially set the latter as the keys are selectively depressed, the improvement which comprises guide means rigidly mounted in said machine frame and effective to guide said key stems in their selection bar setting movements and eliminate aberrant movements of said key stems and selection bars.

10. In a calculating machine, a machine frame, a keyboard including frame structure and keys disposed in ordinal rows and having stems extending slidably through said frame structure, and selection slides extending along said key rows below said frame structure and differentiaily set by depression of keyboard keys in the corres- References Cited in the file of this patent ponding key rows, guide plates extending along said key UNITED STATES PATENTS rows below said frame structure and having notches 1,986,137 Coxhead et a1 Ian. 1, 1935 therein receiving lower portions of said key stems to guide 2 229 889 F 5 1'1 en Jan. 28, 1941 the longltudmal movements of said key stems and reslst the reaction to the force required to difierentialiy set FOREIGN PATENTS said selection slides. 871,541 Germany Mar. 23, 1953 

